Ten days after the U.S. government lifted an alert for possible terrorist attacks in Thailand, the bombs went off. Five people were injured when three devices exploded in central Bangkok on Tuesday, including a man believed to be an Iranian who blew off his own legs while trying to throw a bomb at police. Thailand's Prime Minister Yingluck Shinawatra urged the public not to panic and to wait for security officials to investigate the incident before presuming the blasts were related to terrorism. She scheduled an urgent meeting of Thai intelligence agencies for early Wednesday morning.

On Jan. 13, the United States, Israel and nine other nations warned their citizens in Bangkok of an imminent "possible terrorist attack" after a Lebanese man with alleged links to the Iranian-backed group Hezbollah was arrested and Thai police uncovered more than four tons of fertilizer and other bomb-making materials. Police said at the time that another suspect was still at large. Thai Foreign Minister Surapong Tovichakchaikul strongly criticized the U.S. over the alert, saying there was no threat because the materials were meant to be shipped to another country and not used in Thailand. (Read: "Attacking Israel's Diplomats: The View from Iran.")

It was not immediately clear if the Valentine's Day blasts were related to the earlier arrest or to bombs targeting Israeli diplomats in India and Georgia on Monday. (Israel blamed those attacks on Iran; Tehran denied responsibility.) Thai police said the injured bomber in Bangkok was an Iranian and that they were searching for two other Middle Eastern men who had rented a house with the man in the Sukhumvit area of the capital about one month ago. But Israel's defense minister, Ehud Barak, accused Iran of being behind the bombing in Thailand. He said the explosion "proves once again that Iran and its proxies continue to perpetrate terror." Barak was speaking during an official visit in Singapore and a statement issued by the Israeli Defense Ministry mentioned that he was in Bangkok Sunday.

The first blast occurred in the suspects' house in the early afternoon, according to police, prompting the men to flee. When a taxi refused to pick one of them up, police said he tossed a bomb at the vehicle and continued his flight on foot. The police were by then in pursuit and officers chased him down a side street where they said he attempted to throw a bomb at them, only to have it explode and sever his legs. The incident took place in front of a secondary school, which was immediately evacuated. Police later found C-4 explosives in the house being rented by the men. In the early evening, police said they had arrested a second suspect at Bangkok's international airport. (See more on Monday's attacks in India and Georgia.)

"It is truly alarming that this took place in central Bangkok,'' Panitan Wattanayagorn, a security expert at Chulalongkorn University and a former spokesman for the previous government, tells TIME. "We've always had good relations with Iran. This could be either an isolated incident, part of an arms-smuggling operation, or related to a terrorism organization. In any event, the government needs to do more about how easy it is to obtain access to war weapons.''

Terrorism incidents involving foreign elements are rare in Thailand, although the country has been dealing with an increasingly violent civil conflict in its Muslim-majority southernmost provinces for the past eight years and the capital was rocked by a still-unexplained series of bombs on New Year's Eve in 2006. In a 1994 terrorism-related incident, an Iranian allegedly linked to Hizballah had planned to drive a truck bomb into the Israeli embassy, but was foiled when he got into a traffic accident. (See pictures of the Mahdi scouts: Youth of Hizballah.)

While acts of terrorism are uncommon, Thailand is a nexus for all manner of smuggling  including illegal arms smuggling  because of the ease of movement around the country and relatively lax policing. Terror groups such as the Tamil Tigers of Sri Lanka have used the country as a base in the past, and Hambali, the leader of the al-Qaeda-linked terror group Jemah Islamiyah was apprehended in Thailand in 2003.